Nervous System B Flashcards
What is excitatory
Example: neurotransmitter effects can be excitatory
Excitatory: depolarizing
What is inhibitory
Example: neurotransmitter effects can be inhibitory
Inhibitory: hyperpolarizing
What is direct action?
Neurotransmitter binds directly to and opens ion channels
What is indirect action
Neurotransmitter acts through intercellular second messengers, usually G protein pathways
What are channel-linked receptors
two things
Ligand-gated ion channels and action is immediate and brief
What are G protein-linked receptors
Three things
Responses are indirect, complex, slow, and often prolonged
Involves transmembrane protein complexes
Causes widespread metabolic changes
Describe G protein-linked receptor mechanism
Neurotransmitter binds to G protein-linked receptor, activating G protein
Activated G protein controls production of second messengers, such as cyclic AMP, cyclic GMP, diacylglycerol, or ca2+
Second messenger can then open or close ion channels, activate kinase enzymes, phosphorylate channel proteins, and activate genes and induce protein synthesis
(Essentially know that G proteins function like a relay race)
Describe G protein-linked receptor mechanism (in cartoon form)
Ligand (1st messenger) Receptor G protein Enzyme 2nd messenger
Define neural integration
Neurons functioning together in groups
Define serial processing
Input travels along one pathway to a specific destination
System works in all-or-none manner to produce specific anticipated response
What is the best example of serial processing
Spinal reflex
From which tube does the nervous system originate
Nervous system originates from neural tube and neural crest formed from ectoderm
The neural tube becomes CNS
What does neuron development involve
Proliferation, migration, and the formation of interconnectedness
What is come growth
Prickly structure at tip of axon that allows it to interact with its environment
Are most neurons amitotic after birth
Neurons are amitotic after birth; however, there are a few special neuronal populations that continue to divide
